Mine is a little different. Happened about 3 years back in Muskogee, OK at an auto parts store. I was in there needing some parts for my GTO that had just broken a rear axle shaft. One of the things I needed was a metal brake line ( with the flared ends ). I asked the counterman for one 3 feet long. He disappeared behind the rows of parts on shelves, etc and emerged a moment later with a flared line. After glancing at it, I commented that is looked longer than 36". He took the line, set it on the floor. The floor had the 12 by 12 tiles and it is not uncommon to use them as a measurement reference. He said, "see?, it's exactly 3 feet long").
The only problem was, he had placed the brake line 'diagonally' and not across the tiles. First I thought he was joking with me but, ,he was sincere. I thought that it was so unusual for a grown man to do that. Tactfully, I mentioned that to measure correctly, he would have to place the line 'across' the tiles.
I still chuckle about this to this day.